Historically, service rigs have not been normally used in a drilling mode. They are not designed or equipped for that purpose. However in recent years, with the development of top drives, there has been increasing use of service rigs to deepen wells, drill out cement plugs and drill out bridge plugs. This has meant that the service rig has had to run drill collars and drill pipe to carry out these new drilling operations.
In this connection, difficulties have been encountered in picking up and laying down the drilling tubulars.
For example, in the specific case of drill collars (which are heavy, thick-walled joints of steel pipe), they are typically trucked from a storage yard to the well site and are deposited on timbers laid on the ground. The service rig usually does not have a catwalk and inclined ramp. Therefore, to stand the drill collar up in the service rig derrick, it is necessary for the crew to attach a winch line from the crown of the derrick to the front end of the collar and attempt to manually control the rear end of the collar as the line pulls the front end of the collar up and toward the rig floor, while seeking to avoid having the front end snag the edge of the hinged floor. This operation from time to time leads to damaging the floor or collar threads when the collar snags the floor or alternatively hurting members of the crew as they try to muscle the heavy collar into the proper position. Similar problems occur when the service rig lays down drill collars.
With this background in mind, it is the objective of the present invention to provide apparatus which can be used to bring drilling tubulars to the well site, position the front ends of the tubulars at the edge of the service rig's elevated floor, within reach of the elevators, and provide an inclined ramp along which the rear end of the tubular being stood up can be dragged up to floor level.